The proposed research will provide information on the metabolism of plasmalogens, their precursors and structural analogues in the developing rat brain. The structural specificity of glycerol either formation, glycerol ether cleavage and plasmalogen formation will be studied in vivo by intracerebral injection of C14- and H3-labeled precursors and the results will be substantiated by in vitro experiments using microsomal fractions of developing rat brain and other tissues. Various saturated and unsaturated, straight chain and branched chain alcohols, alkanediols and alkaneketols and their glycerol ether derivatives will be used as substrates. The occurrence and metabolism of phsopholipids having a long-chain 1,2-alkanediol backbone will be investigated. Phospholipid analogues will be used in studies on the substrate specificity of phospholipase A2, phospholipase C and phospholipase D. BIBLIOGRAPHIC REFERENCES: Chang, N., and Schmid, H. H. O., Structural specificity in ether lipid biosynthesis. Formation of hydroxyalkyl and oxoalkyl glycerolphosphatides. J. Biol. Chem. 250, 4877 (1975). Schmid, H. H.O ., Bandi, P. C., Chang, N., Madson, T. H., and Baumann, W. J., Ether lipid metabolism. Incorporation of O-alkyl ethanediol into rat brain lipids. Biochim. Biophys. Acta 409, 311 (1975).